Mature guys take their girls wherever they go (in gatherings) and introduce them to people he knows. More than that, he even makes his parents to meet her to create a sense of familiarity and trust between the two families.
An immature man will take help of dirty humor and sexist remarks as a joke while a mature man will make real, remarkable jokes to make his girl laugh.
The moment which the couple spends together should be cherished whole heartedly and no other concerns should matter. Living in the moment and being spontaneous in showing affections to each other should be done without thinking twice about it.
A mature man is playful in his relationship. Not everyone likes to stay sober all the time and certainly not the girl who expects her man to be fun with her.
Lies ruin a relationship more than anything else does. Being honest might cause a little bit of trouble but would save you from bigger destructions.